ABSTRACT
Nosocomial infections (NI) result in considerably high mortality and morbidity rates, especially among pediatric patients. Considering current worldwide changes, information about the occurrence of pathogens and susceptibility tests are now seen as decisive for optimizing treatment. The purpose of this research was to determine the frequency of microorganisms, antimicrobial and genetic profiles, and risk factors associated with nosocomial infections in a teaching hospital in Campo Grande, Mato Grosso do Sul. From January 1998 to December 1999, 108 patients were characterized as having nosocomial infection, from which 137 pathogens were isolated. Identification and antimicrobial susceptibility was determined by conventional and automated techniques. Staphylococcus aureus and Klebsiella pneumoniae strains were characterized by Pulsed Field Gel Electrophoresis (PFGE). Pathogens were most often isolated from infants one-month old or younger, and bloodstream infections were the most frequent. The main isolated agents isolated were: coagulase-negative staphylococci (38), Pseudomonas aeruginosa (19), S. aureus (26), K. pneumoniae (18), and Candida spp. (13). The risk conditions that were most closely related to NI acquisition were: prolonged hospital stays (69.4 percent), prematurity (60.9 percent) and exposure to high-risk device procedures (95.4 percent). Ciprofloxacin and imipenem were the most effective drugs, inhibiting all or almost all of the Enterobacteriaceae, P. aeruginosa and Acinetobacter calcoaceticus isolates. Only 23 percent of the S. aureus samples were resistant to oxacillin. Genomic typing revealed 10 distinct patterns for S. aureus and 13 for K. pneumoniae, suggesting that most them did not belong to the same clone. PFGE was effective in differentiating the strains